I always recommend that you call your doctor if you're concerned. However, I went and checked over my 'notes' on Period Tracker and I bled for five days after insertion of my Paragard. That is to say, bleeding that required a pad, I bled off and on for a month.

This happened to me with the Mirena. It took several months for my periods to return back to normal. My friend, who happens to be an ob gyn, told me she bled off and on for 6 months after getting hers.